/*
 * Copyright 2017-present Open Networking Laboratory
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.onosproject.mapping.web.codec;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.onosproject.codec.CodecContext;
import org.onosproject.codec.CodecService;
import org.onosproject.codec.JsonCodec;
import org.onosproject.codec.impl.CodecManager;
import org.onosproject.mapping.instructions.MappingInstruction;
import org.onosproject.mapping.instructions.MappingInstructions;
import org.onosproject.mapping.instructions.MulticastMappingInstruction;
import org.onosproject.mapping.instructions.UnicastMappingInstruction;
import org.onosproject.mapping.web.MappingCodecRegistrator;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.notNullValue;
import static org.onosproject.mapping.web.codec.MappingInstructionJsonMatcher.matchesInstruction;

/**
 * Unit tests for MappingInstructionCodec.
 */
public class MappingInstructionCodecTest {

    private CodecContext context;
    private JsonCodec<MappingInstruction> instructionCodec;
    private MappingCodecRegistrator registrator;

    private static final int UNICAST_WEIGHT = 1;
    private static final int UNICAST_PRIORITY = 1;
    private static final int MULTICAST_WEIGHT = 2;
    private static final int MULTICAST_PRIORITY = 2;

    /**
     * Sets up for each test.
     * Creates a context and fetches the mapping instruction codec.
     */
    @Before
    public void setUp() {
        CodecManager manager = new CodecManager();
        registrator = new MappingCodecRegistrator();
        registrator.codecService = manager;
        registrator.activate();

        context = new MappingInstructionCodecTest.MappingTestContext(registrator.codecService);

        instructionCodec = context.codec(MappingInstruction.class);
        assertThat(instructionCodec, notNullValue());
    }

    @After
    public void tearDown() {
        registrator.deactivate();
    }

    /**
     * Tests the encoding of unicast weight instruction.
     */
    @Test
    public void unicastWeightInstrutionTest() {
        final UnicastMappingInstruction.WeightMappingInstruction instruction =
                (UnicastMappingInstruction.WeightMappingInstruction)
                        MappingInstructions.unicastWeight(UNICAST_WEIGHT);
        final ObjectNode instructionJson =
                instructionCodec.encode(instruction, context);
        assertThat(instructionJson, matchesInstruction(instruction));
    }

    /**
     * Tests the encoding of unicast priority instruction.
     */
    @Test
    public void unicastPriorityInstructionTest() {
        final UnicastMappingInstruction.PriorityMappingInstruction instruction =
                (UnicastMappingInstruction.PriorityMappingInstruction)
                MappingInstructions.unicastPriority(UNICAST_PRIORITY);
        final ObjectNode instructionJson =
                instructionCodec.encode(instruction, context);
        assertThat(instructionJson, matchesInstruction(instruction));
    }

    /**
     * Tests the encoding of multicast weight instruction.
     */
    @Test
    public void multicastWeightInstructionTest() {
        final MulticastMappingInstruction.WeightMappingInstruction instruction =
                (MulticastMappingInstruction.WeightMappingInstruction)
                        MappingInstructions.multicastWeight(MULTICAST_WEIGHT);
        final ObjectNode instructionJson =
                instructionCodec.encode(instruction, context);
        assertThat(instructionJson, matchesInstruction(instruction));
    }

    /**
     * Tests the encoding of multicast priority instruction.
     */
    @Test
    public void multicastPriorityInstructionTest() {
        final MulticastMappingInstruction.PriorityMappingInstruction instruction =
                (MulticastMappingInstruction.PriorityMappingInstruction)
                        MappingInstructions.multicastPriority(MULTICAST_PRIORITY);
        final ObjectNode instructionJson =
                instructionCodec.encode(instruction, context);
        assertThat(instructionJson, matchesInstruction(instruction));    }

    /**
     * Test mapping codec context.
     */
    private class MappingTestContext implements CodecContext {
        private final ObjectMapper mapper = new ObjectMapper();
        private final CodecService manager;

        /**
         * Constructs a new mock codec context.
         */
        public MappingTestContext(CodecService manager) {
            this.manager = manager;
        }

        @Override
        public ObjectMapper mapper() {
            return mapper;
        }

        @Override
        public <T> JsonCodec<T> codec(Class<T> entityClass) {
            return manager.getCodec(entityClass);
        }

        @Override
        public <T> T getService(Class<T> serviceClass) {
            return null;
        }
    }
}